1. Field of the Invention
The present invention relates to a counter circuit of a camera so designed that the influence of the pulse signal generated due to the initial chattering caused by the contact of the brush with the conductor can be avoided when the exposure information is converted into the pulse number by means of a brush means sliding over the conductor contacts such as comb tooth shaped conductor pattern.
2. Description of the Prior Art
Generally in case of the exposure amount control device for a camera so designed that various photographic informations are operated into digital values in accordance to which value the shutter speed or the aperture is controlled, the various photographic informations are set in voltages in analog values which voltages are put in the operation circuit in which the various photographic informations are operated as digital value, by converting the voltages into digital values by means of an A - D converter. However, in accordance with the above mentioned method not only A - D converter for converting voltages into digital values is needed but also the circuit composition becomes complicated, which is quite inconvenient for the application in the compact camera.
Consequently, a method has been proposed, whereby a brush is made to slide over the conductor contacts such as comb tooth shaped conductor pattern in functional engagement with the comb tooth shaped conductor pattern, and the pulses whose number corresponds with the number of the contacts of the brush with the contacts are produced and put in the counter such as binary counter in such a manner that the set exposure informations are directly converted into digital value.
However by means of the above mentioned method a chattering takes place at the contact of the brush with the conductor contacts because the pulses are produced by the contact of the brush with the conductor contact, so that at the time of the contact of the brush with the conductor contacts pulses are produced due to the chattering and therefore the pulses to be counted in the counter includes the pulses due to the chattering, which is inconvenient because it is impossible to obtain an exact contact number of the brush with the conductor contacts.